Rock, paper, scissors robot cheats using computer vision

The simple game of rock, paper, scissors is well-known around the world. In a game where it’s human vs. human, you just choose which shape to form your hand into and hope your choice beats your opponent. You can attempt to cheat by delaying your choice until the other player has shown his hand, so to speak, but chances are they will notice and call you a cheater.

Researchers working out of the Ishikawa Oku Laboratory at the University of Tokyo decided to create a robot that can play the game, but is also unbeatable. It achieves a 100% success rate by cheating, but it cheats so fast a human opponent and anyone judging the game would never be able to tell.

The key to the robot’s continued winning streak is computer vision. The robot hand is capable of recognizing a human hand and detecting which shape it makes. Based on that it then chooses a winning response. The reason it will never be caught cheating is because it manages to perform that whole recognition and response process in just 1 millisecond.

You will also notice that the robot hand manages to track and follow the movement of a human hand through the air. This allows the robot to rotate at the wrist joint and perform the two fist shakes before forming into one of the 3 game shapes.

For players, because you can’t tell the robot is cheating you may be inclined to keep playing, convinced you will beat it eventually. But your attempts are futile as this opponent is just an incredibly fast cheater.

The project acts as a demonstration of how very fast computer vision and robot response can be useful for co-operation with humans. The technology could be adapted to follow the actions of a human doing a task that is actually carried out by a robot in order to keep the person safe. For example, performing intricate hand and arm motions within a hostile environment or with volatile materials.